Bring a stock pot of salted water to a boil while you prepare the sauce.
In a large skillet cook the ground beef, breaking it up as it cooks.
When it is browned, add the garlic, red pepper flakes, ginger, brown sugar, beef broth, soy sauce, hoisin sauce and black pepper into the ground beef and stir everything together. The spiciness of the sauce will depend on how many red pepper flakes you put in it. Start small and add more if you want it spicier.
Now, mix your cornstarch with a couple tablespoons of cold water and mix until combined. Add it to your pan and stir into the sauce. It should start to thicken up.
Drain the pasta sauce and add it to the skillet, stir until all is combined.
Garnish with green onions and enjoy!